Rogge, a professor at the University of New South Wales, (UNSW) says his team's approach is a hybrid model that uses optics to excite and manipulate a single atom and electronics to efficiently detect individual spins.

"The first quantum computer is still far away, but this is a major breakthrough and a stepping stone to linking qubits," he says.

Processing power

A quantum bit or qubit is the basic unit in quantum computing and relates to the spin or magnetic orientation of an electron or nucleus of an atom.

In regular computers the "bit" can only have one of two values, 0 or 1. However in a quantum system, the electrons can have both values at the same time, a characteristic known as superposition.

It is this superposition phenomenon that will allow quantum computing to deliver huge increases in processing power. However, for a quantum computer to do calculations that are beyond a conventional computer, researchers estimate it would need to have somewhere in the region of 30 or so qubits operating together.

Lead author Dr Chunming Yin, also of the University of New South Wales, says the new technique overcomes the obstacle of how to link qubits.

"The coupling between different qubits has been a big problem," says Yin. "Using this hybrid approach you don't have to place the atoms spacially close, instead they are coupled by photons [light]."

Optics wavelength

For the study, colleague Associate Professor Jeffrey McCallum, at the University of Melbourne, implanted a single erbium atom into a standard industrial silicon transistor.

A finely tuned laser was then directed at the atom to change its charge state, by making the atom lose an electron. This change was then detected electronically by the transistor.

Yin says the team used the rare earth element, erbium, because it operates at the same wavelength -- about 1540 nanometres -- that is used in modern optical fibre telecommunications.

Rogge says the next step in the work, which also includes researchers from the Australian National University, will be to control the spin of the erbium atom -- a process he believes will be easily achieved.

He says the team is also eager to replicate the technique using phosphorous atoms embedded in silicon so as to take advantage of the advances achieved by UNSW colleagues using those materials.